\section{Evaluation}
The performance of the entire system could be measured using the same metric as
Duygulu et al\cite{duygulu}. That is, we can simply measure the ratio of
correctly labelled image objects. Parts of the system could also be evaluated
separately, we could for instance measure the number of words correctly
identified as words that appear in the image. The number of correctly
categorized images could also be measured. 

The methods of evaluation will need to be refined during the duration of
the project. Results might differ heavily depending of the characteristics of
the input data. We might compare the result from a couple of different books to
give a somewhat more general measurement of the system performance.

